Heretofore, oftentimes when receiving signals from space vehicles or signals that are transmitted over long transmission lines in the form of coded serial data, the signals are distorted. As a result of distortion of the signals and noise, the signals would often be lost or incorrectly verified.
Most of the signals heretofore transmitted from remote transmitters such as carried in space vehicles were transmitted in the form of pulse coded modulated signals of a fixed format which prevented sending and receiving commands during the transmission of the signals. Normally, when utilizing PCM data, you are required to follow the format defined prior to the initiation of the tests. It provides an operator with limited flexibility with regard to data and command signals other than for data that was preprogrammed.
It is important that the data being received from remote locations prior to being utilized or recorded be verified to ensure polarity, sync and validity.
However, it is also desired that data not be discarded solely because it has been distorted to a certain degree. It is important that the signals being received be analyzed so that if the signal comes within a predetermined tolerance set by a programmer, it can be accepted as being accurate even though it is distorted to a certain degree. It is important, however, that this signal be reconstructed into proper shaped information for subsequent use.